Study of optical properties of bulk GaN crystals grown by HVPE
Study of optical properties of bulk GaN crystals grown by HVPE
复制标题
DOI：
10.1016/j.jallcom.2016.03.064
复制
发表时间：
2016-07
影响因子：
6.2
通讯作者：
Hong Gu;Guoqiang Ren;Taofei Zhou;Feifei Tian;Yu Xu;Yumin Zhang;Mingyue Wang;Zhiqiang Zhang
中科院分区：
文献类型：
--
作者：
Hong Gu;Guoqiang Ren;Taofei Zhou;Feifei Tian;Yu Xu;Yumin Zhang;Mingyue Wang;Zhiqiang Zhang
我们研究了用氢化物气相外延生长在同一块晶体上的一系列GaN样品的光学性质。利用阴极发光测量评价了样品的高结晶质量，位错密度范围为2.4 × 106 ~ 2.3 × 105cm−2。采用二次离子质谱法测定杂质浓度，并在3-300 K范围内进行光致发光（PL）测量。我们没有发现O或C杂质与弱黄色发光（YL）带之间的相关性。随着位错密度的减小，带边发射强度增大，YL带边发射强度减小。在低温PL光谱中还观察到与Si和YL波段相关的双电子卫星线之间的竞争，这表明Si杂质在这些GaN样品的弱YL波段中也起着重要作用。这些结果表明，位错周围的Si供体作为浅层供体的合理来源，将与可能的深层受体重新结合并最终与YL反应。
We investigated the optical properties of a series of GaN samples sliced from the same bulk crystal grown using hydride vapor phase epitaxy. The high crystalline quality of the samples was evaluated using cathodoluminescence measurements, and the dislocation density ranged from 2.4 × 106to 2.3 × 105cm−2. The impurity concentration was determined using secondary-ion mass spectroscopy, and photoluminescence (PL) measurements were conducted in the range of 3–300 K. We did not find a correlation between the O or C impurities and the weak yellow luminescence (YL) band. As the dislocation density decreased, the intensity of the band edge emission increased and that of the YL band decreased. A competition between the two-electron satellite lines correlated to Si and the YL band was also observed in the low-temperature PL spectra, which demonstrated that the Si impurity also plays an important role in the weak YL band of these GaN samples. These results indicate that the Si donors around the dislocations, as reasonable sources of shallow donors, will recombine with possible deep acceptors and finally respond with the YL.